And acceptance of Muhammad as God's prophet The Sunni declaration reads لا إله إلا الله محمد رسول الله (lā ʾilāha ʾillallāh, Muḥammad rasūlullāh) (in Arabic) There is no god but Allah, and Muhammad is his messenger (in English)There is no God but Allah and Muhammad is his messenger at 1246 AM Thereupon he (the Prophet) said "Fight with them until they bear testimony to the fact that there is no god but Allah and Muhammad is his Messenger" (Sahih Muslim 5917) The question Ali posed would have been unnecessary had the Muslims been under attack by the Khaybar or if the answer to the question were obvious
Imam Ali In The Kalima Islam From The Start